Live life to the fullest even if it does come crashing down

I am an intelligent person. Well, at least I'd like to think so. My life has never been perfect, but who's has? Even with my flaws in tow I keep pushing forward, showing people that I am capable of things that they may not think I can do. My mind works on levels that other people's minds may not. I have to take my time, and be told in lamens terms for instructions, otherwise, I will not understand what Is being asked of me. I am a little 'slow' and yes I do have to be reminded of things that need to be done because If someone tells me to do something, in 5 mins I won't even recall them saying anything to me. That is how bad my memory has gotten over the years and no amount of brain training games will help that. Believe me, I've tried and its told me I have the memory/mind of a 60-year-old. To hear that when your only 32 makes u depressed. 
Whenever I stay up for hours on end, and I get tired but I still have to do work on the computer and I can barely see what I am writing, or read what's on the page then its time for me to go to sleep but I have trouble sleeping. There is so much going on in my mind that it's hard to quiet it all down. I'll talk to myself silently in my head, conversations going back and forth to myself in the past present and future. I make scenarios up in my head to see how I would react to certain things and fantasize about things that I want to happen in my life. Whether that be a dream job, a business, kids, I can see myself being that person, yet I end up managing to put myself down. 
I've never had a great job, I've never really been good at anything really. well apart from music and that came from a very young age. I have never been confident in myself. I'm not the type of person that can go up to someone and start a conversation. It takes me a while, and until I feel comfortable enough with that person, you won't see me doing it. 
I managed to start doing work for someone, and everything was great to start with but then I had a big family emergency that threw me emotionally and drained me and of course things changed, but the way they made me feel wasn't what I had initially signed up for. I didn't ask for my emotions to be played with, nor did I expect to be spoken to in such a way that put me down and made me feel so low, sometimes to even cry, or laugh at their initial stupidity. I didn't realize a person could do such a thing, especially when my family is involved and my family are  the most important thing to me, more important than doing work for someone I wasn't even getting paid for, and they say they understand but they really don't. Why does life have to be so hard?